ASTEROIDEA iiS 



To make this form the type of a new genus on the strength of its small tooth is to 

 ignore the sum total of the other characters. The highly special pedicellariae in particular 

 are almost signboards to declare the close kinship oi conspicutis and waitei. This is further 

 supported by the skeletal structure and integumentary armature. 



Koehler's type was taken in the same haul with A. conspicuus. 



Type LOCALITY. St. i, Australasian Antarctic Exp., 66° 50' S, 142° 06' £,354 fathoms. 



Distribution. Adelie Land, and Antarctic Archipelago, to 354 fathoms. Note: the 

 specimen recorded by Koehler from no fathoms off Queen Mary's Land (1920, p. 225, 

 pi. 49, figs. 1-3) is perhaps a definitely distinct forma. 



Acodontaster hodgsoni (Bell) 



Heuresaster hodgsoni Bell, 1908, p. 8, pi. 3. 



Tridontaster laserotn Koehler, 1920, p. 214, pi. 47, figs. 7-10; pi. 48, figs. 1-7; pi. 69, fig. 5. 



St. 42. Off mouth of Cumberland Bay, South Georgia, 120-204 m., i specimen (R 74 mm., 

 r 31 mm.). 



Koehler has described and figured this species in great detail. It is regrettable that his 

 name must be replaced by that of Bell who has furnished a figure of the actinal aspect. 

 Otherwise the species could not be identified by Bell's vague description, which is also 

 misleading, since he refers Heuresaster to the Poraniidae ! 



In addition to the Discovery specimen I have examined a slightly larger one from the 

 British Museum labelled St. 316, Terra Nova, 353-55. Both agree in detail with 

 Koehler's description, even to the actinal fasciculate pedicellariae (Koehler, 1920, 

 p. 217, pi. 47, figs. 7, 9). 



Other than having accessory "teeth", this species is an Acodofitaster with small 

 marginal plates of the type of A. conspicuus. In the Discovery specimen there are 2 

 subequal accessory spines on either side of the median tooth and these have little or no 

 hyaline point. In the Terra Nova example three mouth angles have also this second 

 accessory spine without a hyaline tip, while in the first accessory a little of the hyaline 

 point is exposed. 



Now A. conspicuus from St. 42 (as well as from Sts. 149 and WS 865) may have i or 2 

 accessory teeth or spines, without a hyaline tip. As A. hodgsoni was taken along with 

 this specimen of A. conspicuus from St. 42, it was at first believed to be a forma of 

 conspicuus. But it lacks the characteristic pedicellariae. An example oi A. elongatus from 

 St. 181 has 2 (in one case 3) accessory teeth with a short hyaline tip. 



The possession of 3 teeth is a normal variation in Odontaster validus and O. penicil- 

 latus. It is apparently of no greater value here, since there may also be 5 teeth to a 

 mouth angle as readily as 3. 



Type locality. McMurdo Sound, South Victoria Land, 2 fathoms. 



Distribution. Circumpolar. Koehler's specimens were taken off Queen Mary Land 

 (92° to 97° E) 60- no fathoms, and off Adelie Land, 25 fathoms. 



